Pushbutton operated overload switch



April 24, 1962 J. ELLENBERGER 3,031,542

PUSHBUTTON OPERATED OVERLOAD SWITCH Filed Oct. 20, 1960 2 Sheets-Sheet 1 FIG. 2 FIG. 7 FIG .3

April 1962 J. ELLENBERGER 3,031,542

PUSHBUTTON OPERATED OVERLOAD SWITCH Filed Oct. '20, 1960 2 Sheets-Sheet 2 Claims priority, application Germany Oct. 26, 1959 11 Claims. (Cl. 200-116) The present invention relates 'to improvements in a pushbu'tton-operated overload switch which is provided with an automatic release mechanism which may be thermally and/or electromagnetically controlled, as well as with a manual release device. I

In most overload switches of this kind which are presently known a pushbutton is provided for manually releasing the switch. This pushbutton is usually smaller than the main pushbutton for connecting the switch and it is located closely adjacent to the latter. The actuation of the individual pushbuttons is therefore rather difficult, especially if the respective overload switch is of a very narrow construction. It may then occur very easily that when one pushbutton is being depressed, the other may accidentally also be depressed. The desired movement of the control member of the switch which is effected by depressiugone pushbutton will then be counteracted by the unintentional movement of the other pushbutton.

It is an object of the present invention to provide an overload switch, and especially one of a very narrow construction, in whicheach of the two pushbuttons for connecting the switch and for manually releasing it may be separately operated without danger that the other pushbutton may also be operated and in which the manual release button may also be more easily operated than the small pushbutton of the known overload switches which is movable parallel to the connecting button thereof.

This object may be attained according to the invention by providing the manual release button in the form of a two-armed lever which is pivotably mounted within the switch housing and the outwardly projecting end of which, the actual release button, may be operated by pushing it in the direction toward the .axis of the main connecting button. Since the connecting button may be operated by a pressure in a direction vertical to the base on which the switch is mounted, while the lever for manually releasing the switch is operated by a pressure in a direction substantially at a right angle to the direction of movement of the connecting button, it will be practically impossible to operate the release lever while the connecting button is being depressed, or vice versa to pivot the release lever and at the same time to depress the connecting button.

In order to improve the grip on the outwardly projecting or button end of the manual release lever, this end of the lever is provided with an inclined surface which ascends in steps in the direction toward the connecting button. According to a further feature of the invention, the lever is pivotably mounted on a hollow rivet which also serves the purpose of connecting the two parts of the switch housing to each other and-to receive a bolt for securing the switch in a tired position. This hollow rivet obviates the necessity of providing the switch with special bores-or flanges for mounting the same and it also permits the arrangement of several similar overload switches adjacent to each other and to connect them to each other by a bolt which is passed through the hollow rivets in all of these switches. If desired, this same connecting bolt may then also be used to mount the entire row of overload switches. in order to improve this connection the side of the switch housing opposite to that latent 1 ice in which the hollow rivet is secured may also be provided with a recess into which a'further mountng or connecting bolt may be inserted Such a row of overload switches may, for 'eXaniple,be applied in a motor vehicle in place of the conventional replaceable fuses which are inserted in fuse clamps on a common base. For this purpose, the invention further providesthat the terminal strips of each overload switch may be made in the form of plug pins or plug strips'so that the overloadswitch'es may be plugged into the spring'contacts on acomrnon base which may be, for example, of the samekind as used in a motor vehicle for replaceable fuses. Although these plug :pins or plug strips may also project from the switch housing a very compact space saving switch construction may be attained according to the invention by providing the terminal strips which are made in the form of plug pins or plug strips entirely Within the length of the switch.

According to another feature of the invention which is applicable particularly it several overload switches are to be connected to each other, the con'nccting'bolts may also be used for securing angle brackets to the ends thereof. In this case, it will not be necessary to secure the individual switches to a terminal or fuse base since the entire row of switches may then be mounted in a fixed position by means of these brackets. The terminal or fuse base may then be omitted.

Instead of providing the overload switch according to tie invention with terminal strips, the switch may accordin'g'to a further featureof the invention be provided with plug pins which are slottedand may have a thicker bulge on their ends. These plug pins may be held by a clamping action in metal sockets in a base plate, and after being inserted into the sockets from one end thereof, the thicker ends of the plug pins will engage with the edges of the sockets at the other side thereof.

These objects, features, and advantages of the present invention will become further apparent from the following detailed description,particularly when read with reference to theacco-mpanying drawings, in which FIGURE 1 showsa side View of an overload switch according to the invention;

FlGURE 2 shows" a view of the switch 'as seen from the right of FlGUR-E 1;

FIGURE 3 shows a view of the switch as seen from the left of FIGURE 1;

FIGURE- 4 shows a top view of the switch according to FIGURE 1;

FIGURE 5 shows an enlarged side View of the switch according to FIGURE 1 in the opened position and inserted into a fuse base;

FIGURE 6 shows a view of two overload 'switches according to FIGURE 5 and as seen from the right thereof when inserted into a fuse base;

FIGURE 7 shows a side view of a'modification of the overload switch according to the invention;

FIGURE 8 shows a view of the switch according to FIGURE 7, as seen from the left thereof; while FIGURE 9 shows a top View of the switch according to FEGURE 7.

Referring first to FIGURES 1 to 5 of the drawings, the overload switch according to the invention which may be internally designed, for example, in a manner similar to the overload switch as described and illustrated in my previous United States Patent No. 2,895,028, is provided with a housingof insulating material which consists of two parts, in which part 1 contains the various switch elements, while part 2 serves as a cover which secures the inserted elements in a fixed position in part 1. For

electrically connecting the overload switch, the same is provided with terminal strips and 4 which have conical projections 5 and 6 at their ends. When the switch is inserted, for example, into a fuse base 7 as used in a motor vehicle, projection will resiliently engage into a bore 8 in a contact spring 9 which is secured to a connecting terminal 12 on base 7, while projection 6 will engage into a corresponding conicalrecess in a connecting terminal 11. Terminal strip 3fhas a contact 13 thereon which is operatively associated with a contact 14 on an angular contact bridge 15. When contact bridge 15 is in the disconnecting position, as shown, in FIGURE 5, its arm 16 engages with an obliquely inclined surface 17011 the housing part 1 and is held in this position by a pair of projections ls which are provided on both sides of a control rod 19 on pushbutton 20 and are slidably guided in. suitable recesses in the two housing parts 1 and 2. The upper ends of projections 18 engage with a pair of lateral arms 21 on contact bridge 15 and thus pivotably support the latter. Arm 16; on contact bridge 15 is further provided with a large bore into which control rod 19 is inserted and which permits the contact bridge to slide loosely in the axial direction along control rod'19. The lower end of control rod 19 carries a member 22 which is secured thereto and is operatively associated witha projection 23 on contact bridge 15. Control rod 19 carries two compression springs 24 and 25, the first of which actsat one side upon pushbutton 20 and at the other side upon a washer 27 which is inserted into a recess 26 in the housing. The other compression spring which acts at one side upon arm 16 of contact bridge 15 and at the other side upon member 22 efifects the trip-free release of the switch.

For arresting contact bridge 15 in the connecting position, the switch is provided'with a bimetallic strip 28 which has a detent 29 on its free end portion which, when contact bridge 15 is in the connecting position, engages behind contact 30 on arm 16 of the contact bridge. Bimetallic strip 23 carries a heating coil 31 which is electrically connected at one end 32 to the bimetallic strip and at the other end to terminal strip 4.

By means of a two-armed lever 33 which consists of insulating material the bimetallic strip 28 may be manually pivoted to its inoperative position in which detent 29 is disengaged from contact 30 on contact bridge 15. Lever 33 is pivotably mounted on the housing on a hollow rivet 34 which also connects the two housing parts 1 and 2 to each other. i The two parts of the housing are further connected to each other by a second hollow rivet 35. The outer end 33' of lever 33 which projects from housing 1, 2 is provided with a step-shaped inclined Referring particularly to FIGURE 5 which shows the switch in the disconnected position, pushbutton 20 must be depressed in order to engage the switch and to move contact bridge 15 to the connecting position. Member 22 on control rod 19 will then engage with the projection 23 and take contact bridge =15 along until the detent 29 on bimetallic strip 28 will snap over contact 30 on contact bridge 15. By the same movement, contact 14 will also be applied against contact 13 on terminal strip 3 so that the circuit within the overload switch will be closed.

If an excess current occurs, bimetallic strip 28. will be heated by heating coil 31 and thereby be bent toward 4 shown in FIGURE 5, by the projections 13 and the action of compression spring 24. 1

The bimetallic strip 28 may also be bent manually by an operation of lever 33. For this purpose, a pressure is exerted upon the outer end 33' of lever 33 in the direction toward pushbutton 20 so that lever 33 will be pivoted about rivet 34 in the counterclockwise direction and the lower arm 36 of the lever will press upon the outwardly bent tab 28 of the bimetallic strip and thereby bend the latter toward the right so that detent 29' v ing sleeve 40, and nuts 39 may then be screwed tightly At the side of the upon the threaded ends of the bolt. 7 housing opposite to that carrying the hollow rivet 34, a recess 41 is provided into which another bolt 38 may be inserted for further securing the individual switches to each other.

As shown in FIGURE 6, a row of two or morecon V nected switches may be inserted into a fuse orterminal base 7, although such a base may also be omitted, in which event the row of switches may be mounted in a fixed position by means of angle brackets 42 serving as mounting flanges, as indicated in FIGURE 6 in dotted lines, which may be secured to the two outer switches by means of the connecting bolts 38.

In the modification of the overload switch, as illustrated in FIGURES 7 to 9, the two terminal strips 43 and 44 which are likewise made inthe'form of plug pins project from the switch housing 1, 2. This switch is likewise provided with a two-armed lever 33 which is pivotably mounted on a hollow rivet 34 and the outer end 33' of which also projects from the housing and may be easily manipulated in the same manner as described with reference to the switch according to FIGURES l to 6;

If a special terminal or fuse base is to be omitted the terminal strips 3 and 4 may also bemodified in any suitnection to the power lines.

strips may be designed and spaced from each other so as to permit, the overload switch to be plugged into a standard wall plug.

Instead of providing the overload switchaccording to the invention with terminal strips, it is-of course-also possible to provide it with plug pins by designing the switch in a manner similarly as described and illustrated in my previous United States Patent No. 2,767,281, in which case it will not be necessary to connect several adjacent switches to each other by bolts or screwssince the plug pins will then insure a proper and secure mounting of the switches. I

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in noway limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my I invention, what I claim 1s.

1. In an overload switch, in combination, a movable connect-and-disconnect member operable to a connect position and to a disconnect position formaking and breaking an electrical connection, a first pushbutton cooperative with said member having an axis and operable in a direction corresponding with said axis for actuating said member to said connect position, means automatically engageable with said member'forreleasablylocking said =member in said connect position, means constantly urgingsaid member toward said disconnect posi tion, means cooperative with said locking means operable automatically for releasing said member from a lockedcondition when anove'rload occurs, and means operable at will comprising a second pushbutton cooperative with said means for releasably locking said member and operable in a direction normal to said axis for causing said locking means to release said member.

2.'In an overload switch having a housing, in combination, in saidhousing a movable connect-,and-disconnect member in said housing. operable to a connect position and to a disconnect position for making and breaking an electrical connection, a first pushbutton extending outwardly of said housing cooperative with said member having 'an'axis and operable in a direction corresponding with said axis for actuating said member to said connect position, means automatically engageable with said member for releasably locking said member in said connect position, means constantly urging said member toward said disconnect position, means cooperative with said locking means operable automatically for releasing said member from a locked condition when an overload occurs, and means operable at will comprising a second pushbutton extending outwardly of said housing cooperative with said means for releasably locking said member and operable in a direction normal to said axis for causing said locking means to release said member.

3. In an overload switch, having a housing, in combination in said housing connecting means comprising a movable connect-and-disconnect member in said housing operable to a connect position and to a disconnect position for making and breaking an electrical connection, a first pushbutton extending outwardly of said housing cooperative with said member having an axis and operable in a direction corresponding with said axis for actuating said member to said connect position, means automatically engageable with said member for releasably-locking said member in said connect position, means constantly urging said member toward said disconnect position, means cooperative with said locking means operable automatically for releasing said member from a locked condition when an overload occurs, means operable at will comprising a second pushbutton extending outwardly of said housing cooperative with said means for releasably locking said member and operable in a direction normal to said axis for causing said locking means to release said member, and said connecting means comprising terminal strips forming plug pins for connecting said switch in circuit.

4. In an overload switch according to claim 3, in which said plug pins are mounted within the overall length of said housing.

5. In an overload switch according to claim 3, in which said plug pins extend outwardly ofsai'd housing.

6. In an overload arrangement comprising a plurality of overload switches mounted side-by-side, each overload switch having a housing, in each housing a movable connect-and-disconnect member in said housing operable to a connect position and to a disconnect position for making and breaking an electrical connection, in each switch a first pushbutton extending outwardly of said housing cooperative with said member having an axis and operable in a direction corresponding with said axis for actuating said member to said connect position, in each switch means automatically engageable with said mem her for releasably locking said member in said connect position, in each switch means constantly urging said member toward said disconnect position, in each switch means cooperative with said locking means operable automatically for releasing said member from a locked condition when an overload occurs, in each switch means operable at will comprising a second pushbutton extending outwardly of said housing cooperative with said means for releasably lockingsaid member and operable in a direction normal to said axis for causing said locking means to release said member, and means extending betweenthe housings of said plurality of housings for holdingsaid switches in a fixed arrangement in a side-byside disposition.

7. In an overload switch having a housing, in combination, in said housing connecting means comprising a movable:connect-and-disconnect member in said housingoperable to a connect position and to a disconnect position for making and breaking an electrical connection, a-first-pushbutton extending'outwardly of said housingcooperative with said member having an axis and operable in a direction corresponding with said axis for actuating said member tosaid connect position,- means automatically engageable with said member forreleasably lockingsaid member in said connect position, means constantly urging said member toward said disconnect position, means cooperative with said locking means 013- erableautornatically for releasing said member when an overload occurs, means operable at will comprising a second pushbutton extending outwardly of said housing cooperative with said means for releasably locking said member and operable in a direction normal to said axis for causing said locking means to release said member, said connecting means further comprising a two-arm lever cooperative with said second pushbutton and said locking means and operatively connecting them, said housing comprising two parts, at least one hollow rivet connecting said two parts to each other, said lever being pivotally mounted on said rivet, and said rivet having a bore adapted to receive at least one bolt for mounting said switch in a fixed position. I

8. In an overload switch according to claim 7, in which said housing has a slot-shaped opening on a side thereof to receive a mounting bolt.

9. In an overload switch having a housing, in combination, in said housing connecting means comprising a movable connect-and-disconnect member in said housing operable to a connect position and to a disconnect position for making and breaking an electrical connection, a first pushbutton extending outwardly of said housing cooperative with said member having an axis and operable in a direction corresponding with said axis for actuating said member to said connect position, means automatically engageable with said member for releasably locking said member in said connect position, means constantly urging said member toward said disconnect position, means cooperative with said locking means operable automatically for releasing said member from a locked condition when an overload occurs, means operable at will comprising a second pushbutton extending outwardly of said housing cooperative with said means for releasably locking said member and operable in a direction normal to said axis for causing said locking means to release said member, said connecting means comprising plug pins and a base plate having metal sockets for releasably receiving said plug pins, an enlargement on each of said pins, and said sockets for receiving said pins having recesses for releasably receiving said enlargements.

10. In an overload switch, having a housing, in combination, in said housing connecting means comprising a movable connect-and-disccnnect member in said housing operable to a connect position and to a disconnect position for making and breaking an electrical connection, a first pushbutton extending outwardly of said housing cooperative with said member having an axis and operable in a direction corresponding with said axis for actuating said member to said connect position, means automatically engageable with said member for releasably locking said member in said connect position, means constantly urging said member toward said disconnect position, means cooperative with said locking means operable automatically for releasing said member from a locked condition when an overload occurs, means operable at will comprising a second pushbutton extending outwardly of said housing cooperative with said means for releasably locking said member and operable in a direction normal to said axis for causing said locking means to release said member, and said second pushbutton comprising a stepped surface manually engageable for actuating said second pushbutton, disposed outwardly of said housing comprising steps ascending in a direction toward said first pushbutton.

11. In an overload arrangement comprising a plurality of overload switches mounted side-by-side, each overload switch having a housing, in each housing a movable' connect-and-disconnect member in said housing operable to a connect position and to a disconnect position for making and, breaking an electrical connection, in each switcha first pushbutton extending outwardly of said housing cooperative with said member having an axis and operable in a direction corresponding with said axis for actuating said member to said connect position, in each switch means automatically engageable with said member for releasably locking said member in said connect position, in each switch means constantly urging said member toward said disconnect position, in each switch means releasably locking said member and operable in a direction normal to said axis for causing said locking means r 8 cooperative with said locking means operable automatically for releasing said member from a locked condition when an overload occurs, in each switchmeans operable at will comprising a second pushbutton extending outwardly of said housing cooperative with said means for to release said member, means comprising a bolt extending between the housings of said plurality of housings and through said housings forholding said switches in a fixed arrangement in a side-by-side disposition, and atleast one angle bracket secured on one end of said bolt for mounting said' plurality of switches as aunit.

References Cited in the-file of thispatent UNITED STATES PATENTS Belgium Nov. 30, 1955 

